Composite substrate including foldable portion

Abstract

According to one embodiment, a composite substrate includes a soft layer, a hard layer, a rigid portion and a flexible portion. The soft layer includes a first conductor layer with a conductor pattern and a first flexible insulating layer. The hard layer includes a second conductor layer with a conductor pattern and a second rigid insulating layer. The rigid portion is formed by laminating the soft layer and the hard layer. The flexible portion includes a transition portion which is in proximity to the rigid portion by extending the soft layer and is wider than an interconnect portion.

What is claimed is: 
     
         1 . A composite substrate comprising:
 a soft layer comprising a first conductor layer with a conductor pattern and a first flexible insulating layer;   a hard layer comprising a second conductor layer with a conductor pattern and a second rigid insulating layer;   a rigid portion in which the soft layer and the hard layer are laminated; and   a flexible portion comprising a transition portion in proximity to the rigid portion by the soft layer extending away from an outer peripheral edge of the rigid portion, the transition portion wider along the outer peripheral edge than an interconnect portion apart from the rigid portion.   
     
     
         2 . The composite substrate of  claim 1 , wherein
 the second rigid insulating layer covers part of the transition portion across the outer peripheral edge of the rigid portion.   
     
     
         3 . The composite substrate of  claim 1 , wherein
 the transition portion gradually narrows towards the interconnect portion.   
     
     
         4 . The composite substrate of  claim 1 , wherein
 the transition portion comprises the conductor pattern continuing from the rigid portion.   
     
     
         5 . The composite substrate of  claim 1 , wherein
 the soft layer of the flexible portion comprises   a first conductor pattern comprising a signal line connected to an electronic component on the rigid portion; and   a second conductor pattern laminated on the first conductor pattern and comprising a low-strength portion in the transition portion connecting to the interconnect portion with lower pattern density than the rigid portion.   
     
     
         6 . The composite substrate of  claim 1 , wherein
 the soft layer of the flexible portion comprises:   a first conductor pattern comprising a signal line connected to an electronic component on the rigid portion; and   a second conductor pattern laminated on the first conductor pattern, comprising conductivity throughout the interconnect portion and forming a low-strength area with lower pattern density than the rigid portion.   
     
     
         7 . The composite substrate of  claim 6 , wherein
 the low-strength area extends to part of the transition portion.   
     
     
         8 . The composite substrate of  claim 6 , wherein
 the low-strength area is a conductor pattern in a lattice shape.   
     
     
         9 . The composite substrate of  claim 6 , wherein
 the first conductor pattern is on an outer peripheral surface side when the flexible portion is folded.   
     
     
         10 . An electronic apparatus comprising:
 a composite substrate comprising: a soft layer comprising a first conductor layer with a conductor pattern and a first flexible insulating layer; a hard layer comprising a second conductor layer with a conductor pattern and a second rigid insulating layer; a rigid portion in which the soft layer and the hard layer are laminated; and a flexible portion comprising a transition portion formed in proximity to the rigid portion by extending the soft layer away from an outer peripheral edge of the rigid portion, the transition portion, the transition portion wider along the outer peripheral edge than an interconnect portion apart from the rigid portion; wherein   the composite substrate is folded at the flexible portion in a housing.